Inflammation blockade improves pancreatic islet function
Abstract
Pancreatic islet transplantation can replace insulin-secreting β cells in patients with diabetes mellitus. However, current methodology for isolating islets from a pancreas only retrieves a portion of the total islets. Within these limited number of islets, nearly 50% of β cells lose biological function before transplantation. Protecting and improving β-cell viability and function was the goal of this study. Previously we observed that an anti-inflammatory compound, lisofylline (LSF), protects β cells from cytotoxicity during diabetes development. In this study, we demonstrated that human islets treated in vitro with LSF retained β-cell glucose responsiveness and insulin secretion in the presence of multiple proinflammatory cytokines. In addition, LSF treatment in vitro enhanced basal insulin production in β cells, suggesting that LSF can directly improve β-cell function. LSF reduced β-cell apoptosis induced by proinflammatory cytokines by 50%. Importantly, 30% fewer LSF-treated islets were sufficient to achieve insulin independence in a murine islet transplantation model. These results demonstrate the ability of LSF-like compounds to protect and enhance β-cell function, suggesting the potential of using LSF or its analogs in islet transplantation.
University of Virginia, Charlottesville, Virginia
Address reprint requests to Dr Zandong Yang, Department of Internal Medicine, Division of Endocrinology, University of Virginia, PO Box 801413, Charlottesville, VA 22908
Supported by a center grant from the Juvenile Diabetes Research Foundation (#4-1999-805), and grants from the National Institutes of Health (DK062610, DK055240 and DK063609). The authors acknowledge support from the Islet and Cell Core of the Diabetes Endocrine Research Center at University of Virginia.